Expanders / Prefoamers

A well run, good quality Pre-Expander, is vital for any EPS moulder. A lot of money can be lost by problems created at this stage.

Pre-expansion, or prefoaming of EPS raw material to the target moulding density is the first step in Processing of EPS raw materials. It is often treated as the simple step in processing, and quite often the quality of material produced during prefoaming is ignored to the detriment of business profitability. Years of experience demonstrate that you can't fix problems caused during expansion at the silo ageing step or the moulding step of processing. Prefoaming must be done right.

This is why it is critical to understand what happens to the raw material within your prefoamer, to document the process conditions and output quality of material from your expander and learn how to optimize processing conditions with process control to obtain the best possible physical properties.

  1. It must be designed for correct throughput and density target.
  2. It must have correct and consistent steam supply
  3. The process of expansion must be controlled
  4. Quality from the expander dictates quality limits of moulded part - good control is paramount

Polymac agencies for Batch and Continuous Prefoamers include:

There are successful examples from each supplier of prefoamer installations in Australia.

Options include:

  • Single pass and Double pass continuous expanders
  • Single pass and Double pass batch expanders from small to large throughput
  • Expanders with PLC control of the transfer system from the expander to the ageing silos
  • Expanders with Auto density measuring devices
  • Expanders with Auto density measuring and process control to achieve target densities
  • Expanders with drying beds that are vented external to the building
  • Drying bed discharge through venturi or rotary feeder systems

Talk to us about your needs.

We can review your existing system, and recommend machinery options to suit your requirements.